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September 24, 2002 Troubleshooting Replication Problems By Alexander Chigrik
Should you have problems with replication, review this
troubleshooting checklist to find potential solutions.
1. Check the hardware requirements.
For SQL Server 7.0, you should have:
Alpha AXP, Intel or compatible platform
Pentium 166 MHz or higher
64MB RAM or more (recommended)
180MB hard disk space
For SQL Server 2000, you should have:
Intel or compatible platform
Pentium 166 MHz or higher
64MB RAM or more (recommended)
250MB hard disk space
2. Check the software requirements.
To set SQL Server as publisher for merge or snapshot replication,
you can use any edition of Windows XP, Windows 9x, Windows NT 4.0 or Windows 2000.
To set SQL Server as publisher for transactional replication,
you should use one of the following operation systems:
Windows NT Server version 4.0 (with Service Pack 4 or later for
SQL Server 7.0 and Service Pack 5 or later for SQL Server 2000)
Windows NT Server Enterprise Edition version 4.0 (with Service
Pack 4 or later for SQL Server 7.0 and Service Pack 5 or later
for SQL Server 2000)
Windows 2000 Server
Windows 2000 Advanced Server
Windows 2000 DataCenter
SQL Server editions have the following restrictions:
SQL Server 7.0 Desktop Edition cannot be used as publisher
for transactional replication
SQL Server 2000 Personal Edition cannot be used as publisher
for transactional replication
SQL Server 2000 Desktop Engine cannot be used as publisher
for transactional replication
SQL Server 2000 Windows CE Edition does not support snapshot
or transactional replication, and supports only Anonymous Subscriber
to merge replication.
3. Check that you've installed the latest SQL Server service pack.
4. Ensure that the account the MSSQLServer and SQLServerAgent services
run under belongs to the Administrators local group and is a
member of the Domain Users group.
The LocalSystem account does not have network access rights, so
this account should not be used if you want to use replication.
The account the MSSQLServer and SQLServerAgent service runs under
should be a member of the Administrators local group and a member
of the Domain Users group.
5. Ensure that you have sysadmin permissions on the SQL Server.
Only members of the sysadmin server role can configure replication,
so if you do not have these permissions, you will not be able to set up or configure
replication.
6. Ensure that the 'trunc. log on chkpt' option is turned off if you want to set up Transactional replication.
Transactional replication uses the transaction log to capture
changes that were made to data and then sends the
INSERT, UPDATE, and DELETE statements to Subscribers in the same order they
were made in the Publication database.
7. Check the Agent history to determine which task failed and the
reason for failure.
To view the Agent history, you can do the following:
1. Run SQL Server Enterprise Manager.
2. Expand a server group, then expand a server.
3. Expand Replication Monitor and choose the Agent to view history.
4. Right-click appropriate publication and select Agent History...
8. Choose the appropriate Agent profile for your replication model.
For example, if the replication will work through the slow link,
choose Slow link agent profile.
To choose the Agent profile, you can do the following:
1. Run SQL Server Enterprise Manager.
2. Expand a server group, then expand a server.
3. Expand Replication Monitor and choose the Agent.
4. Right-click appropriate publication and select Agent Profiles...
Note. You can also create your own Agent profile (click the
New Profile button under the Agent profile window).
9. Set the rowcount or rowcount and checksum validation to avoid
problems with data consistency.
You can use the sp_table_validation system stored procedure to test for row count or checksum differences.
10. If the Merge Agent or Distribution Agent fails on timeout, increase the QueryTimeout value in the Merge Agent
or Distribution Agent profile.
The QueryTimeout value in the Merge Agent or Distribution Agent
profile indicates the number of seconds before the queries issued
by the agent time out.
To increase the QueryTimeout value in the Merge Agent or
Distribution Agent profile, you can do the following:
1. Run SQL Server Enterprise Manager.
2. Expand a server group, then expand a server.
3. Expand Replication Monitor and choose the Agent.
4. Right-click appropriate publication and select Agent Profiles... 5. Click the New Profile button to create the new profile
with the appropriate QueryTimeout value.
6. Choose the newly created profile.
11. If you receive an "Access Denied" error when starting the Snapshot
Agent, make sure the account the SQL Server Agent runs under
has default access and launch DCOM permissions.
To check/set it, you can do the following:
1. Run Dcomcnfg.exe.
2. Click the Default Security tab.
3. Check that the account that SQL Server Agent runs under has default
access and launch DCOM permissions.
12. Make sure that the snapshot folder is shared correctly.
Otherwise, replication agents cannot access the snapshot folder,
and you will get replication error. For example, on a distributor
server running Windows 9x, the snapshot folder defaults to using
the local path without a share. So, you should change the local
path to a network path by sharing the folder manually.
13. If you get a "Couldn't deliver schema information" error when
synchronizing the Internet publications, set up FTP server at the
Distributor and set the Merge Agent command line to include an
FTP address.
Because a UNC path, which is used by default, works only in the Local
Area Network (LAN) for Wide Area Networks (WAN), you should use
a FTP address instead.
14. If conflict occurs when merging newly inserted rows that
contain identity columns, you must assign each Subscriber
that will insert new rows containing an identity a unique
range of identity values.
Try to avoid using identity columns in the tables that will be
replicated.
15. You cannot specify the uniqueidentifier column with the
ROWGUIDCOL property as the primary key of the published table
when you use merge publishing from SQL Server to Jet 4.0.
To work around this, you can use a composite primary key with two
columns (uniqueidentifier column and integer column, for example).
16. Use a ALTER TABLE statement instead of using the Design Table in
SQL Server 7.0 Enterprise Manager tool to modify a table that has
the NOT FOR REPLICATION property.
Otherwise, the NOT FOR REPLICATION property on the IDENTITY column
will be lost.
17. Use the Replication Conflict Viewer to get more information about
conflict details.
Replication Conflict Viewer is a Wzcnflct.exe file that can be
executed from the command prompt. You can run Replication Conflict
Viewer from the SQL Server Enterprise Manager. To run Replication
Conflict Viewer from the SQL Server Enterprise Manager, do the following:
1. Run SQL Server Enterprise Manager.
2. Expand a server group, then expand a server.
3. Expand Replication Monitor and choose the article.
4. Right-click article and select View Conflicts...
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